High voltage electrical transmission lines are common place for moving electricity from a generating plant to a desired location where electricity is needed. Such electrical transmission lines comprise thick electrical conductor lines which are suspended from high metal towers. Large insulators are connected at one end to the conductor lines and at the other end to the tower or to a hinged gate carried by the tower.
The large transmission lines pass over all types of terrain. The tension on the conductor lines is typically 7,000 to 10,000 pounds in order to keep the lines well supported above the ground between the spaced towers. When the transmission line changes direction the conductors place a significant sidewise force on the towers. When the conductor lines are attached to insulators carried by hinged gates on the tower the hinged gates sometimes allow the conductor lines to hang too close to the tower structure itself.
In such cases it is often necessary to re-hang the lines so that they are not suspended too close to the tower structure. Although it is possible to repair or make modifications to the conductor line suspension system by taking down the conductor lines, this is extremely undesirable because of the expense associated with taking down the conductor lines and because of the lost revenue resulting from having the transmission line inoperative for an extended period of time. Sometimes it is possible to use large cranes to support the conductor lines when making repairs to the suspension system, but this requires use of very expensive equipment, and oftentimes it is not possible to maneuver such large equipment to the required site because of rough terrain. Also, these large towers are constructed to support high tension conductor lines on both sides of the tower. Consequently, if the conductor lines are disconnected from one side of the tower there is presented a danger of the entire tower being pulled over or collapsed due to the tension on the opposite side of the tower. If one such tower collapses it is possible that adjacent towers may also collapse due to the force exerted by the high tension conductor lines.
Thus, making repairs or modifications to the suspension system on these large towers has been a difficult, delicate and expensive undertaking.